Reign of Terror Starter Guide
Getting Started in Grim Dawn: Reign of Terror

Mod made by Ram

Guide Written by Birds


Reign of Terror is a full remake (not a 1:1 copy) of the classic ARPG Diablo II, and includes all content and classes present in the original Diablo II, including its expansion, Lord of Destruction. It uses all the original sounds and music, and even all the cut scenes available in-game. In addition to this, as this is a Grim Dawn mod, it also features all Grim Dawn Classes and items, and all of the core mechanics of Grim Dawn.

Since the core mechanics cannot be changed, a perfect Diablo II replica is not possible. This is as close as it can be however.

This starters guide has been written for those new to the Grim Dawn: Reign of Terror mod, new to Diablo II and for those who know Diablo II, but don’t know how all the mechanics work here. This guide will also list some of the differences compared to Grim Dawn. 

If you are completely new to Grim Dawn, and wish to learn about the Grim Dawn mechanics, I’d recommend reading the starters guide on the official Crate forum or on the Grim Dawn subreddit.  Also, play the original game. Grim Dawn is an amazing ARPG with great atmospheric storytelling and a well thought out class and skill system.

To play Reign of Terror, you need the base game as well as the Ashes of Malmouth and Forgotten Gods expansion. There are manual downloads per patch available, but also a RoT Launcher, which does all the updating automatically!

There is a RoT discord available where many questions can be answered as well, in case you cannot find them in this guide or on the Wiki.

Getting Started
Leveling and Choosing a Class

Grim Dawn takes a different approach to the class system, in that it lets you start with a blank character. The moment you level up, you get to pick from any of the available classes, either from Grim Dawn or Diablo II. Once you reach level 10, you get to pick a second class. Be warned, once you put points in your second class, this cannot be undone!

Something to keep in mind, the skills from Diablo classes have a maximum rank up to 20, while the GD classes often don’t go further than 12. This makes the Diablo skills much stronger for the end-game content. However, the GD classes offer many support skills. It is recommended to choose at least 1 Diablo class.

Every time you gain a level, you get 1 attribute point and 3 skill points up till level 90. From level 91-100 you get 4 skill points per level. The Grim Dawn attributes, Physique, Cunning and Spirit have been renamed to their Diablo II versions: Strength, Dexterity and Intelligence. Strength will increase life, life re-gen and defense, dexterity will increase attack rating and physical damage types (physical, trauma, pierce and bleeding) and intelligence increases maximum mana, mana regeneration and damage from magic sources (magic, fire, lightning, acid, chaos, etc). More on attack rating and defense later.


As you progress through the game and complete the quests you get devotion points. You will get 1 devotion point per completed quest. Once you have finished all difficulties there is a total of 81 devotion points (versus the maximum of 55 in Grim Dawn). The devotion system is quite intimidating at first. If you are new to it I recommend using the search function, and search for the desired damage type you wish to aim for. That will make it easier to decide which devotions to pick. Don’t worry about experimenting though, you can reclaim your devotion points (and skill points) free of charge in every town.

If you feel overwhelmed by all the possibilities, there are builds posted in the RoT Discord and on this wiki. Follow these or use them as a starting guide.


Reign of Terror has 3 (or 4) difficulty modes: Normal, Nightmare and Hell. In addition, you can play an increased difficulty Normal+, Grim Dawn’s Veteran mode, as well. Be warned though. Normal+ is much harder compared to Veteran mode. As this is a mod, all 3 difficulties are available from the start. However, unlike Grim Dawn, enemies do not scale with the player level. Instead, they are fixed per zone.

On average, monsters hit a lot harder in RoT compared to GD, so resistances are even more important (even on normal difficulty). Try to get your elemental (fire, cold, lighting) and poison resistances up as high as you can.

Attacking rating and defense (AKA: Offensive ability and Defensive ability) are also very important, but especially for the end-game content. These will determine your chance to hit and score critical hits and lower the chance of being hit or getting hit with a critical yourself.

Items & Gear

*RoT characters are not compatible with other mods. So if you use your RoT char in another mod or base game, all your RoT items will probably get deleted as well as losing all quest progress.*

You will find a lot of gear, of several qualities. Those used to Diablo II will recognize the coloring right away, but those new to Diablo (and more experienced to GD) might be confused for a moment. The quality and coloring goes, from low to high, as follows normal, magic, rare, set, unique. There is a convenient loot filter available in-game to get rid of those pesky normal items cluttering up your screen. Use the button (a ring icon) just left of your health bar to open the loot filter.

*All Diablo II items are in the game. Every unique and set item as well as every runeword in at least 1 weapon type.*

Gems and Runes

Gems and runes are items which work similar to the normal components of Grim Dawn. You can apply 1 component to each item (except for the Relic which cannot accept a component). You can retrieve a component from an item, but the item will be destroyed in the process. Vise versa, if you wish to keep the item but remove the component, you will lose the component. 

Rainbow Facets

There is a special component called Rainbow Facet.  These will convert 25% of one damage type into another (all combinations possible) and as such, are great build makers. Want to play lightning fury amazon and occultist together, but afraid of having no synergy?  No worries, convert all lightning damage to vitality damage!  Keep in mind, to calculate your damage output: first apply your conversion, then multiply by the %damage bonus you have of the new damage type.  Conversions apply to all abilities (unless otherwise stated), including devotion skills, item skills and retaliation. 

Augments and Mercenaries

Augments are bought in every act. Before you can see them on the vendor, you need to have a minimum level. For example, the highest level augments (level 90) won’t appear in Act V Hell difficulty until your character is at least level 90. The lowest level augments start from level 40. You can remove or replace augments from gear, but the augment will be lost.

Mercenaries are added in the form of a medal augment, adding a ‘summon’ skill.  *If you wish to use a new medal or new mercenary, you will simply have to buy a new one.*  There is no saving the old mercenary. Mercenaries’ abilities scale with the player level and player abilities.  Mercenaries cannot be equipped with any items, not like in Diablo II.

While leveling, Prayer Act II Mercenary will help a lower level, or new player stay alive better in the early game of RoT.

Crafting and Cube

The standard Grim Dawn blueprints will drop throughout your play-through, or are bought from a mysterious boy. Look for an anvil and forge to craft the Grim Dawn gear and components, and to remove components etc. 

Diablo 2 items, such as gems, runes and runewords are crafted using the Horadric Cube. To use the cube, right click it in your  inventory. A little golden cube will appear on the ground. Interact with this to open the cube’s crafting menu. Much like a portable anvil.


Socketed items are needed for runewords. They act as crafting materials, so don’t try to socket multiple gems or runes in them. Runewords are likely to be your strongest items while leveling and for end-game content. After your make a runewords, there is no retrieving the runes or the socketed weapon/armor base.


The main storyline happens in Act I till Act V. RoT mod also has the Shattered Realm (SR) available. The Shattered Realm is Grim Dawn’s version of Diablo IIIs Greater Rifts. This is the only area where monsters scale with the player level. The SR is reached by using the green portal in the basement of the house in the Rogue Encampment in Act 1. 

A Thing of Legends

There are more secrets to be discover though. People have mentioned pesky goblins who smell like manure, giggling as they run off with their stolen loot, disappearing to another place. Where might they go to?

Legends speak of incredible monsters and demons hidden away in their secret lairs. The ever cryptic Ram, who guards over the Shattered Realm, seems to know more about their whereabouts.

Faint whispers in the shadows mention unspeakable demons. The whispers urge you to collect their keys and release them. Do you dare seek them out?